1. Field of the Invention
The invention relates to a method of producing a firm bond between a rigid subcomponent which comprises a polyamide containing thermoplastic composition and a flexible subcomponent comprising a vulcanized fluoroelastomer. The invention also relates to the articles obtained by this method.
2. Discussion of the Background
Composite materials comprising stiff thermoplastic molded materials and rubber-elastic molding materials are customarily joined together by adhesive bonding, screwing, mechanical interlocking or using a coupling agent. Recently, interesting methods of producing composites comprising a polyamide-based molding and a vulcanizate have been developed. Thus, EP-A-0 344 427 describes the production of a composite comprising polyamide and a rubber containing carboxyl or anhydride groups, while in EP-A-0 629 653 the rubber compound contains an unsaturated silane. The adhesive strengths achieved are notable but the method has some disadvantages. Thus, if the concentration of reactive groups in the rubber compound is relatively high, undesired adhesion to the metal mold customarily used in vulcanization can occur. In addition, for some applications it is extremely disadvantageous that the resistance of the elastomers used toward oils, fats, solvents and fuels, e.g. super-grade gasoline, diesel or alcohol-containing fuels is unsatisfactory, particularly at high temperatures.
Objects of the invention are therefore, starting out from the abovementioned prior art, as follows:
Use should be made of a commercial rubber which does not have to be additionally functionalized or modified and also requires no specific additions of reactive agents; PA1 in the production process, the composite bodies should have no undesirable adhesion to the walls of the mold and should therefore be able to be removed from the mold without problems, PA1 furthermore, the vulcanizate should be resistant to oils, fats, solvents and fuels over a wide temperature range, PA1 finally, the adhesion at the phase interface of the composite should not be adversely affected by contact with oils, fats, solvents or fuels over a wide temperature range and over a long period of time. PA1 said polyamide containing thermoplastic comprises at least 30% by weight of polyamide and in said polyamide at least 30% of the end groups are amino end groups; PA1 comprising vulcanizing a fluororubber compound while in contact with said polyamide containing thermoplastic.